This disclosure relates to polycarbonate compositions, and in particular to polycarbonate compositions that include impact modifier compositions, their use in laminated articles, methods of manufacture, and uses thereof. Blends of polycarbonate with impact modifier compositions are useful in many engineering applications because they exhibit a balance of moldability, heat resistance, moisture resistance, impact strength and good flame retardance ratings. For example, polycarbonate/acrylonitrile-butadiene-styrene blends are used to manufacture housings for desktop and laptop computers, cell phones, computer printers, etc. However, when they burn, these blends generate too much smoke for them to be useful in transportation and construction applications such as train, bus, or aircraft interior and exterior parts, for which stringent low smoke generation requirements are imposed for passenger safety. Similarly, in building interiors, there is a strict requirement on the amount of smoke that can be generated from plastic parts to ensure human safety in the event of a fire. For this reason, polyimides, polyaramides such as Kevlar® and polyetherimides are extensively used in aircraft interiors, high temperature automotive lighting bezels, under the hood automotive applications, etc. However these polymers are very expensive and difficult to process and do not provide the mechanical properties exhibited by polycarbonate compositions. For example, polyetherimides generally have poor impact strength and flow properties relative to polycarbonates.
U.S. Pat. No. 5,986,016 discloses polyetherimide resin compositions with improved low temperature ductility comprising polyetherimide; siloxane-polyetherimide copolymer; up to 35 wt. % polycarbonate and/or copolyester-carbonate; and glycidyl ester and/or polycarbonate-polysiloxane copolymer impact modifier.
There remains a need in the art for polycarbonate resin compositions that include impact modifiers but that do not produce excessive smoke upon being burned and that exhibit good processability and good mechanical properties.